As per my research Google has been using the spark icon to represent AI features since before the recent AI boom. I traced the spark icon back to Google products from years ago.

In 2020 Google Photos update uses the ✨ spark for auto enhancements. And the Google Docs Explore feature from 2016, which helps discover topics without leaving your document, also displays the now iconic spark icon.

This reveals that Google was already attaching this visual design element to AI functionality over 5 years ago. However, Google Trends shows searches for AI really only gained momentum starting in 2022, spiking in 2023.

So Google was almost foreshadowing the AI wave with this consistent spark icon years before. They linked the icon to AI-enabled features across products like Photos, Docs and News far earlier than industry hype grew around AI.

Helpful links:

Ai Trends - https://trends.google.com/trends/explore?date=today%205-y&q=ai&hl=en

Google Photos 2020 updates -

https://blog.google/products/photos/new-helpful-editor/

Google Docs 2016 updates -

https://blog.google/products/docs/explore-docs-sheets-and-slides/

This question is genuinely intriguing. I will certainly revise my article to encompass these aspects. Thank you!